Cheddar Corn Chowder

Name: Cheddar Corn Chowder
Ingredients: 8 ounces bacon, chopped; 1/4 cup good olive oil; 6 cups chopped yellow onions (4 large onions); 4 tablespoons (1/2 stick) unsalted butter; 1/2 cup flour; 2 teaspoons kosher salt; 1 teaspoon freshly ground black pepper; 1/2 teaspoon ground turmeric; 12 cups chicken stock; 6 cups medium-diced white boiling potatoes, unpeeled (2 pounds); 10 cups corn kernels, fresh (10 ears) or frozen (3 pounds); 2 cups half-and-half; 1/2 pound sharp white cheddar cheese, grated